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# tseep

Because there are N fastest event emitters. And we are fastest (feb 2023) 😏.

Up to **x12** faster than `eventemitter3` in terms of "classic api event emitters" (currently fastest for not classic too).

---

-   Fully typed args of `emit` method based on events map
-   Fully implements `NodeJS.EventEmitter` type & standart, provides interface
-   Worlds fastest pure-js `EventEmitter`
-   Fully tested with eventemitter3 tests
-   No external deps

[how it works](./docs/how_it_works_en.md)

## Benchmarks

emit-multiple-listeners:
```
tseep x            40,569,711 ops/sec  <---
EventEmitter1 x     4,498,223 ops/sec
EventEmitter2 x     4,536,296 ops/sec
EventEmitter3 x     5,852,395 ops/sec
fastemitter x       6,127,215 ops/sec
event-emitter x     3,449,595 ops/sec
contra/emitter x    2,186,002 ops/sec
tsee x              5,231,167 ops/sec
emitix x            6,549,983 ops/sec 
Fastest is [ 'tseep' ]
```

[benchmarks](./benchmarks/README.md)

Make an issue to include yours event emitter, lets find the fastest!

## Install & use

```
npm i tseep
```

Simple usage:

```ts
import { EventEmitter } from "tseep";

const events = new EventEmitter<{
    foo: (a: number, b: string) => void;
}>();

// foo's arguments is fully type checked
events.emit("foo", 123, "hello world");
```

## Api

`EventEmitter<T>` where `T` extends `{ [eventName]: Call signature }`.

`EventEmitter.emit`'s args is fully typed based on events map.

!! **`__proto__`** event name is restricted (type guard exists) !!

```ts
// Listener = (...args: any[]) => Promise<any>|void
// EventMap extends { [event in (string|symbol)]: Listener }

class EventEmitter<EventMap> {
    readonly maxListeners: number;
    readonly _eventsCount: number;

    emit(event: EventKey, ...args: ArgsN<EventMap[EventKey]>): boolean;
    on(event: EventKey, listener: EventMap[EventKey]): this;
    once(event: EventKey, listener: EventMap[EventKey]): this;
    addListener(event: EventKey, listener: EventMap[EventKey], argsNum?: ArgsNum<EventMap[EventKey]>): this;
    removeListener(event: EventKey, listener: EventMap[EventKey]): this;
    hasListeners(event: EventKey): boolean;
    prependListener(event: EventKey, listener: EventMap[EventKey]): this;
    prependOnceListener(event: EventKey, listener: EventMap[EventKey]): this;
    off(event: EventKey, listener: EventMap[EventKey]): this;
    removeAllListeners(event?: EventKey): this;
    setMaxListeners(n: number): this;
    getMaxListeners(): number;
    listeners(event: EventKey): EventMap[EventKey][];
    rawListeners(event: EventKey): EventMap[EventKey][];
    eventNames(): Array<string | symbol>;
    listenerCount(type: EventKey): number;
}
```

## License

MIT